MicroRNAs (miRs) are endogenous non-coding ˜22 nucleotide RNAs that affect the protein expression of their target genes by transcript cleavage or translation blockade. More than 400 microRNAs have been identified in the human genome. MicroRNAs belong to one of the largest gene families and account for ˜1% of the genome. More than 30% of the human genome is estimated to be under miRNA post-transcriptional control, although the number of validated miRNA targets remains small. MicroRNAs are implicated in a number of processes including cellular differentiation, proliferation and apoptosis (e.g., cardiac and inflammatory diseases).